How to connect ordinery speaker to a computer??

How to connect ordinery speaker to a computer(speaker next to a red and black wire to connect)??

Answer:
Is the "ordinary" speaker amplified? Does it plug into the wall? If not you will requirement an amplifier as a computer only provides "line level" outputs.

Then you will stipulation a headphone jack to RCA style adapter. Plug the headphone end to the computer and the RCA to the receiver/amplifier.

Amplifiers designed for computers are rate at 4Ω and are unsuitable for "ordinary" 8Ω speakers.

Hope this helps!
You entail a buy a jack plug. The inner part of the terminal is positive (red wire) and the outer part of the pack is negative. or simply buy a all set made wire next to jack plug standard size ( be sure that it is stereo) then basically connect the wires accordingly. If you own a soldering tools, the better. Use electrical tape to stamp the wires.